I'll start by saying that before SWTOR, the last MMOs I played were PlanetSide and a bit of EVE Online. In other words, I had very little MMO experience and thus hesitated buying SWTOR, given the MMO gameplay mechanics that I know aren't at all like what I'm used to (e.g. BF3, Skyrim, etc). Nevertheless, I'm a massive Star Wars fan and had a gift voucher from Christmas so I went for it (the price was high then but the new price is AMAZING).
I rolled a Jedi Knight on a PvE server and was instantly hooked, within minutes. I wasn't a big fan of the art style (as I prefer photorealistic graphics) but hey, it was Star Wars and it was a hell of a lot of fun. As soon as I got into it though, none of my gripes mattered - I was simply having tons of fun levelling, going through the story, experimenting, etc.
Three months have now passed and I still play several hours per day (when I can find the time). My Jedi Knight is now a Sentinel at level 50. I also have a Gunslinger and a Sith Marauder. That's the beauty of it - you can just roll different class characters from both sides (Republic and Empire) and play through a completely different storyline (side quests are the same, though, but differ between Republic and Empire).
PvP is a lot of fun as well but after playing for some months, it is clear that the game needs more content. No sweat though - that is an MMO, receiving new content again and again. I can't wait for patch 1.2 as it will add tons of stuff to the game, including the much anticipated Legacy system.
The recent patches have also fixed many of the bugs that plagued the game, including performance problems. Sure, SWTOR could use some extra performance from patches but for now it's at least stable. My system can certainly munch through this game without a hitch but initially SWTOR taxed it more than BF3, which is weird and clearly showed the engine needed further optimisations via patches. All in good time, though.
Overall, I thoroughly recommend SWTOR to anyone into MMOs and anyone into Star Wars. Trust me, you don't have to be into MMOs to love this game as long as you are really into Star Wars. If I wasn't into Star Wars, I wouldn't enjoy it as much (since I'm not a big MMO player anyway). With the new price tag though, including the free first month, this is a must!!